Process for the production of hydantoins

Abstract

The invention relates to a new process for the production of compounds containing at least one hydantoin ring by reacting a carbodiimide with a derivative of an α,β-unsaturated carboxylic acid corresponding to the following general formula: ##STR1## wherein R 3 , R 4 and R 5 are as defined in the description.

We claim: 
     
       1. A process for the production of a compound having at least one hydantoin ring, wherein a polyimide is reacted with an acid corresponding to the formula ##STR11## wherein R 3  and R 4  represent hydrogen or an alkyl radical; R 5  represents a CN-- group, a CHO-- group, COOR 6  -- group or ##STR12##  in which R 6 , R 7  and R 8  represent alkyl, cycloalkyl, alkenyl or alkinyl; at temperatures of from about -20° to 250° C.   
     
     
       2. A process according to claim 1 wherein the reaction preceeds in contact with a solvent and a catalyst. 
     
     
       3. A process according to claim 2 wherein the solvent is methylenechloride or a mixture of solvents containing methylenechloride. 
     
     
       4. A process according to claim 1 wherein the polyimide is a linear or branched polycarbodiimide. 
     
     
       5. A process as claimed in claim 1 wherein said polyimide is of the formula   --Y--N═C═N--.sub.n     wherein   Y represents at least one aliphatic radical containing 2 to 12 carbon atoms, cycloaliphatic radical containing from 5 to 12 carbon atoms or C 6  -C 16  aryl radical or diphenyl radical attached through O, S, SO 2 , CH 2 , CH 3  --C--CH 3  or CO or --Si(R 6 ) 2  -- or Sn(R 6 ) 2  -- group; and   n represents an integer of from 2 to 2000.